WCA January 2015

Technology news

Increasing accuracy

Worldwide GER GER SA, Belgium, is a supplier of quality second hand wire and cable machinery with worldwide activities. One of its key activities is the purchase and sale of straightening and cutting machines for smooth and/or ribbed wires. The machines are available in “as-is” condition as well as mechanically and electrically reconditioned or with new electrics. Extensions of existing outlet tables or new outlet tables in any required length are also being offered. Once a machine has undergone thorough reconditioning the buyer is invited to witness a test run prior to shipment. Installation and comm- issioning by GER’s staff is also possible. GER SA – Belgium Website : www.ger.be

This extends from the in-house calibrating laboratory through accredited calibrating laboratories up to the national metrological institute. Different standards, regulations and guidelines are valid for the expert carrying out of calibrations. A unit must fulfil basic requirements before it can be calibrated. One must also be aware of the physical conditions required in order to carry out a calibration and observe them. Rules for the calibration of instruments are essential when a company decides on adhering to a specific norm or guideline or if it produces a product whose production is subject to legal regulations. The benefits of a Zumbach measuring unit include: • Calibration and self-calibration functions of ODAC ® measuring heads • Measuring units are calibrated using reference standards which were certified by the federal office for metrology (www.metas.ch) or by accredited laboratories. Each unit is supplied with a detailed calibration protocol • A regular check for measuring errors along with the corresponding protocol can be carried out according to the customer requirements. The regularity of these calibrations is dependent on the customer-specific requirements (internal regulations). Zumbach recommends a check every 12 to 24 months • All the measuring heads of the ODAC ® series have a self-calibration function (Patent DE3111356) which makes subsequent regular calibration superfluous, except when exchanging components All the relevant parameters for accuracy are continuously monitored by the measuring system and automatically compensated when required. This is particularly important for possible ageing effects of the scanner motor or the possible long-term drift of the measuring electronics. Zumbach Electronic AG – Switzerland Website : www.zumbach.com

CALIBRATION measurement technology means establishing the measurement deviations on the measuring unit. During the calibration no technical intervention occurs at the measuring instrument, as opposed to adjusting where an instrument is set or adapted to keep the errors as small as possible or that the number of errors does not exceed the error limits. The official calibration of a measuring unit is carried out according to the rules and regulations of the examining authority and the unit is marked with the respective stamp. The examining authority establishes whether the measuring unit fulfils the respective prerequisites. The validity of a calibration period follows practical requirements such as manufacturer information, requirements of quality standards or company internal and customer-specific regulations, rather than an official calibration with a fixed time period validity for use. in

In order to be able to compare results of measurement, it must be possible to feed back information via a chain of comparison measurements to a national or international master. For this purpose, the display of the unit in use or the material representation must be compared with the masters in one or more stages. At each of these stages a calibration is carried out with a master which has been previously calibrated with a higher-level master. According to the ranking of the master – of consumption or factory standards via reference masters up to national standards – there is a calibration hierarchy of points to be carried out. ❍ ODAC ® measuring unit with reference calibration standards

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Wire & Cable ASIA – January/February 2015